+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   12310 Londontario (1992 DE4) Classification: Main-belt Asteroid          SPK-ID: 2012310 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 30 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1879145759444463 3.842e-08   a 2.731884331010898 1.1236e-08 au q 2.218523445419708 1.0525e-07 au i 1.702872564916693 3.6871e-06 deg node 141.347582493749 0.0001463 deg peri 225.5915880751809 0.00014661 deg M 233.8637344132985 1.0804e-05 deg tp 2459578.368945131437 (2021-Dec-29.86894513) 5.1354e-05 TDB period 1649.270487592825 4.52 1.0175e-05 2.786e-08 d yr n .2182783253009238 1.3467e-09 deg/d Q 3.245245216602088 1.3348e-08 au   Orbit Determination Parameters    # obs. used (total)      1473      data-arc span      15978 days (43.75 yr)      first obs. used      1976-09-25      last obs. used      2020-06-24      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .5433      source      ORB      producer      Otto Matic      solution date      2020-Nov-13 02:53:50   Additional Information  Earth MOID = 1.2176 au   Jupiter MOID = 2.21535 au   T_jup = 3.327  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 14.3   n/a MPO435817   diameter diameter 8.361 km 0.156 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.053   0.003 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   12310 Londontario           Discovered 1992 Feb. 29 by Spacewatch at Kitt Peak. The Canadian city of London, Ontario, founded in 1854, is located at the fork of the Thames River, midway between Lake Erie and Lake Huron. It is a center of education, health care and commerce. The name was suggested by P. Jedicke and R. Jedicke. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20050523/MPCPages.arc Last Updated: 2005-07-21 [ show close-approach data ] Alternate Designations  1992 DE4 = 1976 SJ7 = 1985 RW5  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-21 09:50 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin